Latest news with #Moncla
Yahoo
06-02-2025
- Health
- Yahoo
Second strain of bird flu found in Nevada dairy cows
Dairy cows in Nevada have been infected with a new strain of bird flu virus different from the one circulating in other herds throughout the past year, the U.S. Department of Agriculture (USDA) said. The strain found in the Nevada cattle raises new questions about the spread of the avian influenza virus in dairy cows, which many assumed began after the virus jumped from birds in Texas. The newer version of the virus matches the strain currently found in wild birds and domestic poultry, as well as in the severe human cases — a Louisiana man who died in January, and a Canadian teen who was hospitalized for more than two months and nearly died. The virus has never before been seen in cattle, ruling out the possibility that the Nevada cows caught it from another infected herd. Michael Worobey, an evolutionary biologist at the University of Arizona, said the initial hope was that a rare mutation allowed the virus to jump from birds and settle in cattle. 'Now, we know that's not true,' Worobey said. 'It means that we might be playing Whac-A-Mole with it just jumping in over and over again, and the tools that we hoped to use to get rid of [the virus] might not work as well.' This is also the second known instance of cattle becoming infected after the virus jumped from wild birds, which experts said shows that cattle are susceptible to other H5N1 viruses, not just the specific subtype that started in Texas and has since infected 950 dairy herds in 16 states, according to USDA. 'Right now it's unclear how widespread this is. But given D1.1's prevalence in wild and domestic birds right now, we should be aggressively testing exposed dairy cattle who are near H5-positive poultry premises to see whether this phenomenon is present beyond Nevada,' Louise Moncla, a pathobiologist at the University of Pennsylvania, said in an email. But since testing has not been very thorough in many states, given the reluctance of farmers to get their herds tested, it's possible there have been other undetected instances of the virus spilling over from birds to cattle. The USDA said the detection of this version of the virus was confirmed Jan. 31 after it was found in raw milk collected from a silo as part of a national milk testing strategy that started in 2024. Federal officials have maintained there is a low risk to the general public, and experts said there doesn't appear to be a change based on the new findings. But Moncla also noted the human cases associated with exposure to infected cattle have been mild, while at least one severe case has come after exposure to wild birds or backyard flocks. 'Though it's too soon to make any conclusions about this, it is concerning. We don't yet know if these viruses are better at infecting people. But if they are, then introduction into dairy cattle could enhance human exposure risk,' Moncla said. Worobey said he is leading a team of scientists to try to find out how long the latest strain was circulating in cattle before it was discovered. But he said the finding diminishes the prospect that the virus could be eliminated from cattle entirely, because it was a much different version of the virus that made the jump from birds into cattle. The immunity built up in the dairy cattle population against bird flu may not hold up well against the D1.1 genotype. 'The cattle might have to start fresh in terms of building up immunity to this strain as well,' Worobey said. There are also concerns about potential vaccines, and whether they might be so specific to the first variant that they won't help block transmission of the new variant. There are currently no licensed H5N1 vaccines for cows, but some are in development. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
The Hill
06-02-2025
- Health
- The Hill
Second strain of bird flu found in Nevada dairy cows
Dairy cows in Nevada have been infected with a new strain of bird flu virus different from the one circulating in other herds throughout the past year, the U.S. Department of Agriculture (USDA) said. The strain found in the Nevada cattle raises new questions about the spread of the avian influenza virus in dairy cows, which many assumed began after the virus jumped from birds in Texas. The newer version of the virus matches the strain currently found in wild birds and domestic poultry, as well as in the severe human cases — a Louisiana man who died in January, and a Canadian teen who was hospitalized for more than two months and nearly died. The virus has never before been seen in cattle, ruling out the possibility that the Nevada cows caught it from another infected herd. Michael Worobey, an evolutionary biologist at the University of Arizona, said the initial hope was that a rare mutation allowed the virus to jump from birds and settle in cattle. 'Now, we know that's not true,' Worobey said. 'It means that we might be playing Whack-a-Mole with it just jumping in over and over again, and the tools that we hoped to use to get rid of [the virus] might not work as well.' This is also the second known instance of cattle becoming infected after the virus jumped from wild birds, which experts said shows that cattle are susceptible to other H5N1 viruses, not just the specific subtype that started in Texas and has since infected 950 dairy herds in 16 states, according to USDA. 'Right now it's unclear how widespread this is. But given D1.1's prevalence in wild and domestic birds right now, we should be aggressively testing exposed dairy cattle who are near H5 positive poultry premises to see whether this phenomenon is present beyond Nevada,' Louise Moncla, a pathobiologist at the University of Pennsylvania, said in an email. But since testing has not been very thorough in many states, given the reluctance of farmers to get their herds tested, it's possible there have been other undetected instances of the virus spilling over from birds to cattle. The USDA said the detection of this version of the virus was confirmed Jan. 31 after it was found in raw milk collected from a silo as part of a national milk testing strategy that started in 2024. Federal officials have maintained there is a low risk to the general public, and experts said there doesn't appear to be a change based on the new findings. But Moncla also noted the human cases associated with exposure to infected cattle have been mild, while at least one severe case has come after exposure to wild birds or backyard flocks. 'Though it's too soon to make any conclusions about this, it is concerning. We don't yet know if these viruses are better at infecting people. But if they are, then introduction into dairy cattle could enhance human exposure risk,' Moncla said. Worobey said he is leading a team of scientists to try to find out how long the latest strain was circulating in cattle before it was discovered. But he said the finding diminishes the prospect that the virus could be eliminated from cattle entirely, because it was such a different version of the virus that made the jump from birds into cattle. The immunity built up in the dairy cattle population against bird flu may not hold up well against the D1.1 genotype. 'The cattle might have to start fresh in terms of building up immunity to this strain as well,' Worobey said. There are also concerns about potential vaccines, and if they are so specific to the first variant that they're not going to help block transmission of the new variant.
CNN
06-02-2025
- Health
- CNN
New bird flu infections in Nevada dairy cattle signal the virus may be here to stay
Six dairy herds in Nevada have tested positive for a newer variant of the H5N1 bird flu virus that's been associated with severe infections in humans, according to the Nevada Department of Agriculture. Scientists say these infections with a different type of virus mark an inflection point in the nation's efforts to contain the virus: It may be here to stay. The strain is not the same one that has been circulating in other dairy herds throughout the United States, a virus called B3.13. The newer version, D1.1, has previously been detected only in birds and in people who had contact with infected birds. This is the first time it has been found in dairy cattle, meaning that these cows caught it from wild birds, instead of another infected herd. This is the second known instance of a type of avian flu being introduced into cattle herds by birds and It suggests the virus could be seeding itself into herds through introductions from wild birds, which are ubiquitous. That could mean the H5N1 infection might become endemic, or continuously circulating, in birds in North America, and that may eventually spell trouble for people, too. 'In my opinion, it is now endemic, and it should be classified as an endemic virus,' said Dr. Louise Moncla, a pathobiologist at the University of Pennsylvania who runs a lab that studies how viruses emerge in human populations and spread. The US Department of Agriculture currently classifies H5N1 as a foreign animal disease, meaning an infectious disease in animals that is not currently present in the United States. In an October news briefing, Dr. Eric Deeble, deputy undersecretary for marketing and regulatory programs at the USDA, said agriculture officials were still confident that H5N1 could be eliminated in the national herd. Experts said repeated infections of cattle by wild birds will make that that possibility more remote. 'It's much easier to control virus spread when you're talking about a virus spreading from cow to cow than controlling spread from birds to cows,' said Dr. Scott Hensley, a microbiologist who studies the evolution of flu viruses at the University of Pennsylvania's Perelman School of Medicine. This isn't the first time the US has had to contend with such a destructive bird flu outbreak. In 2014, highly pathogenic H5N8 bird flu viruses from Europe arrived in North America, resulting in the destruction of more than 50 million commercially farmed birds. This aggressive culling worked. North America remained free from highly pathogenic bird flu viruses for years. Moncla thinks this go-round with the virus will be a different story, however. Moncla and her team recently posted a preprint study on how the H5N1 virus was introduced in North America in late 2021 and quickly found its way onto farms. By studying the evolution of the virus, they determined spread into poultry flocks was driven by somewhere between 46 and 113 different introductions of the virus from wild to farmed birds. Now, she says, with the virus spreading in so many different species of mammals and birds, it is likely to be here to stay. Though all six of the recently infected Nevada herds are located in the same valley, Dr. J.J. Goicoechea, director of the Nevada Department of Agriculture, said that after conversations with the farmers and with his state veterinarian, they believe the infection was introduced separately at each of the dairies by wild birds. Goicoechea said there doesn't seem to be a lot of movement of people or equipment between the dairies, which have been following strict biosecurity protocols. He said the state is working with the US Department of Agriculture on genetic testing to see if there are changes to the virus that might help them understand its spread. D1.1 has been associated with two severe infections in people: a teenager in British Columbia who was hospitalized in critical condition last fall but eventually recovered and a senior in Louisiana who died from their infection in January. Farm workers in Washington state have also tested positive for D1.1 after culling infected poultry. Their symptoms were described as milder. Scientists are studying the D1.1 strain to try to learn more about its capabilities and how it appears to be spreading so aggressively. 'D1.1 was initially found, I believe, in August of 2024 in the Pacific Flyway. It's now in all four flyways, and so we know it's in the environment, but this is the first time it's been documented that D1.1 has been in a dairy cow,' said Goicoechea. The affected dairies have provided the Nevada Department of Health and Human Services with contact information for workers who are being monitored for signs of infection, and they are being offered personal protective equipment, Goicoechea said. To date, no humans have tested positive in connection with the infected herds in Nevada. Notably, the D1.1 infections in cows do not appear to be more severe than B3.13 infections, Goicoechea said. 'We're seeing exactly the same clinical signs,' Goicoechea said. Cows lose their appetite, and their milk production drops. Most recover with veterinary care. 'It's very, very similar signs to what we've seen for really the last year, since this started in Texas and Kansas,' he said. The newly infected Nevada herds were detected on January 31 through a US Department of Agriculture program that is testing milk in large silos across the US. 'Lots of different bulk tanks from different farms can come into one silo. And then they trace it back,' said Dr. Seema Lakdawala, a microbiologist and immunologist at Emory University who has been studying how the H5N1 virus is infecting cows. Lakdawala says the finding raises critical questions about how dairy cattle are being exposed and whether it's possible to contain the H5N1 outbreak, which is rapidly spreading among animals and birds, though health officials say most people are still at low risk from the virus. Since March 2024, H5N1 avian influenza has been detected in 957 herds in 16 states, according to the USDA. There have been 67 infections confirmed in humans in the US, nearly all of them farm workers who had contact with infected animals, according to the CDC. That number is believed to represent a fraction of the true number of human infections, however. A CDC study testing the blood of exposed farmworkers found 7% of them had developed antibodies against the virus, suggested they had previously been infected. Get CNN Health's weekly newsletter Sign up here to get The Results Are In with Dr. Sanjay Gupta every Friday from the CNN Health team. A recent study published in the New England Journal of Medicine on the first 46 documented human infections in the US determined that all had mild symptoms that began with red, inflamed eyes and a fever. None of these first patients who became ill after contact with sick animals was hospitalized. Researchers don't know why most human infections with avian flu in the US — which have primarily been with the B3.13 strain — have been mild. One reason may be that H5N1 is clumsy at infecting people. It prefers to latch onto a certain configuration of a sugar called a sialic acid that's plentiful on the cells of birds. Humans have these kinds of sialic acids, too, but they're relatively rare on cells in the human respiratory tract, which is where flu viruses need to land to make us really ill. Scientists agree that the more H5N1 spreads, the more likely it is to change in ways that could help it get better at infecting people. 'I would say everybody's really interested in D1.1 right now, because it seemingly came out of nowhere and then caused two very severe human infections,' Moncla said. 'So people are quite worried about it.'
New York Times
27-01-2025
- Health
- New York Times
‘This Is a Dangerous Virus'
When bird flu first struck dairy cattle a year ago, it seemed possible that it might affect a few isolated herds and disappear as quickly as it had appeared. Instead, the virus has infected more than 900 herds and dozens of people, killing one, and the outbreak shows no signs of abating. A pandemic is not inevitable even now, more than a dozen experts said in interviews. But a series of developments over the past few weeks indicates that the possibility is no longer remote. Toothless guidelines, inadequate testing and long delays in releasing data — echoes of the missteps during the Covid-19 pandemic — have squandered opportunities for containing the outbreak, the experts said. In one example emblematic of the disarray, a few dairy herds in Idaho that were infected in the spring displayed mild symptoms for a second time in the late fall, The New York Times has learned. In mid-January, the Department of Agriculture said that no new infections in Idaho herds had been identified since October. But state officials publicly discussed milder cases in November. That a second bout of infections would produce milder symptoms in cattle is unsurprising, experts said, and could be welcome news to farmers. But reinfections suggest that the virus, called H5N1, could circulate on farms indefinitely, creating opportunities for it to evolve into a more dangerous form — a 'high-risk' scenario, said Louise Moncla, an evolutionary biologist at the University of Pennsylvania. 'You could easily end up with endemically circulating H5 in dairy herds without symptoms, obscuring rapid or easy detection,' Dr. Moncla said. It's impossible to predict whether the virus will evolve the ability to spread among people, let alone when, she and others said. But the worry is that if bird flu finds the right combination of genetic mutations, the outbreak could quickly escalate. 'I'm still not pack-my-bags-and-head-to-the-hills worried, but there's been more signals over the past four to six weeks that this virus has the capacity' to set off a pandemic, said Richard Webby, an influenza expert at St. Jude Children's Research Hospital. Federal officials, too, have subtly altered their tone in discussing the outbreak, now emphasizing how quickly the situation might change. For the general public, H5N1 is 'a low risk, relative to the other risks they face today,' said Dr. Nirav Shah, principal deputy director of the Centers for Disease Control and Prevention. But '100 percent, that could change,' he said. 'This is a dangerous virus.' Health experts emphasize that there are precautions Americans can take: Do not touch sick or dead birds or other animals; get tested if you have flulike symptoms; do not consume raw milk or meat, or feed them to your pets. If a larger outbreak were to erupt, the federal vaccine stockpile holds a few million doses, although that vaccine might first need updating to match the evolved form of the virus. In either case, officials would have to scramble to produce enough for the population. The C.D.C. recommends treatment with the antiviral Tamiflu, but studies have shown that the drug does very little to ease illness. Underlining concerns among many experts is that Robert F. Kennedy Jr., who would lead the federal health department if confirmed, was a vocal critic of Covid vaccines and has said the bird flu vaccines 'appear to be dangerous.' Even if the second Trump administration embraces vaccine development, as the first one did when Covid bore down, it's unclear how many Americans would roll up their sleeves for the shots. Influenza typically affects children and older adults, and pandemic influenza has sometimes hit young adults the hardest. But the mistrust engendered during Covid-19 may make Americans eschew precautions, at least initially. An evolving threat Unlike the coronavirus, which caused havoc with its sudden arrival, influenza viruses typically start off in a specific animal species or in certain geographical regions. When H5N1 emerged in East Asia nearly three decades ago, it mostly sickened birds. In the years that followed, it infected at least 940 people, nearly all of whom had close, sustained contact with infected birds; roughly half of those people died. But since January 2022, when the virus was detected in wild aquatic birds in the United States, it has affected more than 136 million commercial, backyard and wild birds, helping to send egg prices soaring. It has also struck dozens of mammalian species, including cats both wild and domesticated, raccoons, bears and sea lions. For at least a year, H5N1 has been infecting dairy cattle, which were not known to be susceptible to this type of influenza. In some cows, it has had lasting effects, reducing milk production and increasing the odds of spontaneous abortions. And in 2024, the virus infected 67 Americans, compared with just one in the years before, in 2022. The sources of these infections are not all known; one person may have transmitted the virus to someone in their household. Many of these developments are classic steps toward a pandemic, said Dr. James Lawler, a director at the University of Nebraska's Global Center for Health Security. But, he noted, 'where those were really supposed to trigger accelerated and amplified actions at the federal, state and local level, we've just kind of shrugged when each milestone has passed.' Infections in dairy herds, which first emerged in Texas, appeared to be declining last summer. But in late August, California announced its first case. The state's figures soon rose sharply, prompting Gov. Gavin Newsom to declare a public health emergency in December. 'That was sort of a flag to me, like, 'OK, this hasn't gone away,'' said Dr. Manisha Juthani, commissioner of the Connecticut Department of Public Health. 'Over the last couple of months, it has felt like the tempo has increased,' she said. Several other recent events have raised the level of alarm among experts. In early December, scientists reported that in a lab setting, a single mutation helped the virus infect human cells more efficiently. And late last year two people, a 13-year-old Canadian girl and a Louisiana resident older than 65, became seriously ill; previously, most people infected with H5N1 had not experienced severe symptoms. The Louisiana patient, who had health conditions and cared for sick and dying birds, died in early January. The girl was placed on life support because of organ failure, but eventually recovered. Scientists still do not know how she became infected; her only risk factor was obesity. Both patients had contracted a new version of the virus that is distinct from the one in dairy cattle and is now widespread in birds. In both individuals, the virus gained mutations during the course of infection that might allow it to better infect people. 'We are clearly now getting novel viruses forming in the wild bird reservoir,' Dr. Moncla said. 'It's become challenging to keep a handle on all of the various threats.' Some experts see it as particularly worrisome that the virus seems to be in food sources like raw milk and raw pet food. Domesticated cats have died in numerous states, prompting the recall of at least one brand of pet food and new federal guidelines on pet food quality. 'The raw-pet-food thing to me is, I think, quite alarming,' said Dr. Jeanne Marrazzo, director of the National Institute of Allergy and Infectious Diseases. Pasteurization kills live virus, as does cooking meat at high temperatures. Still, neither procedure is perfect, Dr. Marrazzo noted: 'There's no way that you can police production and sterilization in a way that's going to make sure 100 percent of the time that food supply is going to be safe.' A flawed response In the year since the outbreak began, federal officials have announced other measures to prevent or prepare for a pandemic. But each is deeply flawed, experts said. The U.S. Department of Agriculture was slow to begin testing H5N1 vaccines for cows, leaving interested companies in limbo. Dr. Marrazzo said that the department had released genetic information from virus samples but had not said where or when they were collected — details that would help scientists track the virus's evolution. It is also unclear how many herds are reinfected or have been battling monthslong infections. In Idaho, some herds infected in the spring seemed to recover but showed milder symptoms again in November. 'From the data we have to date, we do not see evidence of new infections or reinfections in previously affected herds, but rather a lack of clearance of the original infection,' a spokesman for the U.S.D.A. said in an emailed response. But outside experts said that the trajectory of symptoms suggested a second round of illness. The U.S.D.A.'s program to test bulk milk began in December — nearly a year after the outbreak began — and still does not include Idaho. Engaging private companies may help the program move faster. Ginkgo Bioworks, a company that worked with federal agencies during the Covid pandemic, already assesses roughly half the nation's commercial milk supply for bacteria, antibiotics and other substances. Adding H5N1 to the list would be straightforward, so 'why wouldn't we just add assays into this infrastructure that we already have?' said Matt McKnight, a manager at the company's biosecurity division. Earlier this month, the Biden administration announced $306 million in new funding, about one-third of it for surveillance, testing and outreach to farmworkers. But farmworkers in some places like the Texas Panhandle are still unaware of what bird flu is, how it spreads and why it should matter to them, said Bethany Alcauter, director of research and public health programs at the National Center for Farmworker Health. As a result, she said, many workers still do not use protective gear, including in milk parlors where the virus is thought to spread. Human testing has been voluntary, and infections have been missed. Few farmworkers have opted to be tested, out of fear of immigration officials or their own employers. 'If you don't look for it, you won't find it, right?,' said Dr. Deborah Birx, who served as White House Coronavirus Response Coordinator under President Trump. 'This is not about lockdowns or restricting activity. It's about protecting the individual American by empowering them with the information.'
